The gustatory system in vertebrates consists of at least two separable components: that innervated by the facial nerve, and that innervated by the vagal-glossopharyngeal complex. Catfish and goldfish are to be used as the animal models for studies on the anatomy of central nervous system pathways involved in gustation. Horseradish Peroxidase (HRP) will be used as a tracer substance to determine the input/output relationships of the gustatory lobes. Differences between the vagal and facial lobes will be sought in terms of reflex or long ascending connections. Immunohistochemical and cytochemical differences in the gustatory lobes will also be sought. Studies just completed indicate that L-enkephalin immunoreactivity is very heavy both in the vagal taste structures and the general visceral sensory nucleus, but is largely lacking in the facial lobe. Similar differences will be sought using antisera directed against other neuropeptides. Lesion and HRP studies will be used in an attempt to determine the source of any extrinsic neuropeptide sytems.